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#!/usr/bin/env python3
# Copyright (c) 2021 Cisco and/or its affiliates.
#
# SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
#
# Licensed under the Apache License 2.0 or
# GNU General Public License v2.0 or later; you may not use this file
# except in compliance with one of these Licenses. You
# may obtain a copy of the Licenses at:
#
# http://www.apache.org/licenses/LICENSE-2.0
# https://www.gnu.org/licenses/old-licenses/gpl-2.0-standalone.html
#
# Note: If this file is linked with Scapy, which is GPLv2+, your use of it
# must be under GPLv2+. If at any point in the future it is no longer linked
# with Scapy (or other GPLv2+ licensed software), you are free to choose
# Apache 2.
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Traffic script for IPsec verification."""
import sys
from ipaddress import ip_address
from scapy.layers.l2 import Ether
from scapy.layers.inet import IP, TCP
from scapy.layers.inet6 import IPv6, ICMPv6ND_NS, ICMPv6MLReport2
from scapy.packet import Raw
from .TrafficScriptArg import TrafficScriptArg
from .PacketVerifier import RxQueue, TxQueue
def check_ipv4(pkt_recv, dscp):
"""Check received IPv4 IPsec packet.
:param pkt_recv: Received packet to verify.
:param dscp: DSCP value to check.
:type pkt_recv: scapy.Ether
:type dscp: int
:raises RuntimeError: If received packet is invalid.
"""
if not pkt_recv.haslayer(IP):
raise RuntimeError(f"Not an IPv4 packet received: {pkt_recv!r}")
rx_dscp = pkt_recv[IP].tos >> 2
if rx_dscp != dscp:
raise RuntimeError(f"Invalid DSCP {rx_dscp} should be {dscp}")
if not pkt_recv.haslayer(TCP):
raise RuntimeError(f"Not a TCP packet received: {pkt_recv!r}")
def check_ipv6(pkt_recv, dscp):
"""Check received IPv6 IPsec packet.
:param pkt_recv: Received packet to verify.
:param dscp: DSCP value to check.
:type pkt_recv: scapy.Ether
:type dscp: int
:raises RuntimeError: If received packet is invalid.
"""
if not pkt_recv.haslayer(IPv6):
raise RuntimeError(f"Not an IPv6 packet received: {pkt_recv!r}")
rx_dscp = pkt_recv[IPv6].tc >> 2
if rx_dscp != dscp:
raise RuntimeError(f"Invalid DSCP {rx_dscp} should be {dscp}")
if not pkt_recv.haslayer(TCP):
raise RuntimeError(f"Not a TCP packet received: {pkt_recv!r}")
# TODO: Pylint says too-many-locals and too-many-statements. Refactor!
def main():
"""Send and receive TCP packet."""
args = TrafficScriptArg(
[u"src_mac", u"dst_mac", u"src_ip", u"dst_ip", u"dscp"]
)
rxq = RxQueue(args.get_arg(u"rx_if"))
txq = TxQueue(args.get_arg(u"tx_if"))
src_mac = args.get_arg(u"src_mac")
dst_mac = args.get_arg(u"dst_mac")
src_ip = args.get_arg(u"src_ip")
dst_ip = args.get_arg(u"dst_ip")
dscp = int(args.get_arg(u"dscp"))
ip_layer = IPv6 if ip_address(src_ip).version == 6 else IP
sent_packets = list()
pkt_send = (Ether(src=src_mac, dst=dst_mac) /
ip_layer(src=src_ip, dst=dst_ip) /
TCP())
pkt_send /= Raw()
sent_packets.append(pkt_send)
txq.send(pkt_send)
while True:
pkt_recv = rxq.recv(2, sent_packets)
if pkt_recv is None:
raise RuntimeError(u"ICMPv6 echo reply Rx timeout")
if pkt_recv.haslayer(ICMPv6ND_NS):
# read another packet in the queue if the current one is ICMPv6ND_NS
continue
elif pkt_recv.haslayer(ICMPv6MLReport2):
# read another packet in the queue if the current one is
# ICMPv6MLReport2
continue
# otherwise process the current packet
break
if pkt_recv is None:
raise RuntimeError(u"Rx timeout")
if ip_layer == IP:
check_ipv4(pkt_recv, dscp)
else:
check_ipv6(pkt_recv, dscp)
sys.exit(0)
if __name__ == u"__main__":
main()
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